摘要
根据多孔介质中的力学理论 ,推导了在地壳中存在微孔洞时介质的应力应变本构关系的表示公式 ,讨论了描述地壳中空洞形成过程的孕震模型参数 ,讨论了孕震模型参数的变化与地壳介质状态的变化和地面重力变化的关系 ,并根据乘法分解理论推导了孕震过程计算重力变化的弹塑性递推计算方法 ,并采用 GTN模型进行了数值模拟。在此基础上 ,将数值模拟结果与发生在 1 996年云南丽江 Ms=7.0地震前后的重力变化进行了对比分析 ,讨论了微孔洞的形成过程与地面重力变化的关系 ,较合理地解释了丽江 Ms7.0地震前后的重力变化过程。
On the basis of the mechanical theory in the porous media the relationship between stress and strain is deduced when there exist micro holes in earth crust.The parameter K which describes the breaking process in earth crust is discussed.The physical meanings of state of the earth crust change with K and the formulas which express gravity variation with k are also derived. The gravity variation distribution on earth surface is calculated by using GTN model.The gravity variation from 1992 to 1996 in southwest China,Yunnan province where Lijiang M s=7.0 earthquake occurred in 1996 is compared with computed results. At last, the process of gravity variation during Lijiang earthquake is explained reasonably.
出处
《地壳形变与地震》
CSCD
2000年第1期8-16,共9页
Crustal Deformation and Earthquake
基金
国家自然科学基金资助项目!( 49774 2 14 )
国家九五科技攻关项目!( 96 9130 7)
关键词
地壳
孕震过程
重力变化
地震成因
seismic process, gravity variation, GTN model, micro hole.
